Traditionally metal pipes, such as copper pipes, are used for potable water systems. However, metal pipes may be expensive, in part due to volatile metal prices, and their assembly may be cumbersome. Moreover, minerals in the water inside the pipe together with variation in the pH value may cause rapid corrosion in copper, for example. The corrosion in the copper causes an unsightly green layer on the outer surface of the pipe. Further, harmful substances may dissolve from the copper into the water inside the copper pipe.
Plastic pipes, such as pipes made of cross-linked polyethylene, are becoming extensively used for potable water systems. The possibilities to use them in surface mounting are, however, limited.
Document EP 0691193 discloses a multilayer composite pipe. The multilayer composite pipe is formed such that an inner layer is first extruded and coated with tie material. Thereafter an aluminium band is wrapped around the inner layer and welded such that a longitudinal welding seam is formed. The aluminium layer is coated with an outer plastic layer.
DE 2939388 discloses making of a pipe that has an inner layer made of plastic. Seamless metal layer, for example of aluminium, is pressed on the outside of the plastic layer.
WO 2007/088252 discloses a multilayer composite pipe. The multi-layer composite pipe comprises an inner layer of plastic and a seamless tubular metal layer over the inner layer. The metal layer may be covered with an outer plastic layer.
Flexible hoses are also known. EP 2154403 discloses a flexible hose having a metallized look. DE 19511216 discloses a double-walled flexible hose having an inner layer and an outer layer. Between the inner layer and the outer layer there is a colour layer. WO 02/101276 discloses a flexible plastic tube having a metallic appearance. The tube has an inner layer of plastic and a film outside the inner layer, which film has a metallic appearance. On the top of the layer having the metallic appearance there is an outer at least partially transparent protective layer. EP 0685675 discloses a flexible hose for sanitary applications, especially for the shower. The coloration and/or metallisation is achieved by a film which is hot pressed onto the pipe. EP 1197700 discloses a flexible hose having an inner layer of rubber or silicone and a decorative film of metallized plastic outside the inner layer. DE 7714185 discloses a flexible tube made of plastic, such as polyvinyl chloride, and having a spiral formed metal film wrapped around it. The metal film is covered with an outer plastic layer. DE 19737676 discloses a flexible hose having two metal coloured straps wound around a plastic hose. An outer hose is provided outside of the metal coloured straps. EP 0886741 discloses a flexible protective sleeve comprising a wall made of heat resistant plastics. The sleeve also comprises a layer of infra-red radiation-reflecting metal vacuum deposited on the outer surface of the wall. U.S. Pat. No. 5,555,913 discloses a plastic hose with a colouring and/or metallisation on its surface. The colouring and/or metallisation is produced by stamping on a hot stamping film. Flexible hoses may be used in shower or gardening hoses, for example. Their use in potable water systems and especially in surface mounting is, however, very limited.
WO 00/61977 discloses a stainless-plastic composite pipe.
CN 2492730 discloses a pipe having an inner pipe layer of plastic, an outer pipe layer of aluminium alloy and a protective layer of corrosion resistant metal material. The corrosion resistant metal material is coated with a coating layer of polishing electrophoresis.
DE 29807448 discloses a structure having an inner layer of polyvinyl chloride and an outer layer of chromed brass.
GB 2111164 discloses a composite pipe having a plastic inner layer which is surrounded by a longitudinally-fed metal foil coated on both sides with an adhesive. An outer layer of plastic is extruded onto the metal foil. The pipe is used in floor heating systems.
WO 01/85430 discloses a multilayer metal composite tube. A plastic lining is applied by extrusion to the interior of the metal tube and a plastic coating is applied to the exterior of the metal tube.
CA 1292154 discloses a metal pipe coated with a zinc film. A chromate film covers the zinc film. An intermediate layer consisting substantially of an epoxy resin covers the chromate film. A polyvinyl fluoride film covers the intermediate layer.
WO 2005/014279 discloses a pipe that has an inner metal body. The inner metal body has a coating comprising a zinc layer, a silicate layer and a synthetic resin layer.
EP 1316751 discloses a multilayer pipe. The multilayer pipe includes two tubular layers of plastic material, an inner layer and an outer layer and two intermediate metal layers.
Despite the numerous prior art there is clearly a need for a new pipe that is well suited for use in surface mounted installations.